Stabilization of organic compounds



I I 2,843,495 I a STABILlZATION or ORGANICCOMPOUNDSY 5 Joseph A. Chenicek, Bensenville, 111., assignor to Universal Oil Products Company, Des Plaines, Ill-,a cor-,

poration "of Delaware serial N -4 63 0.

1N5 Drawing; Application November I 7 Claims. 995463) Y This 'inventionrelates to the stabilization 'of organic compounds which tend to deteriorate in storage, transporta'tion and/or in use :due tooxidation, polymerization and/or other reactions. More particularly, the present inventionrelates to a novel method of preventing and/orretarding deterioration of organiccompounds by incorporating therein a mixture of particular additives.

The novel method of the present invention may be utilized for the stabilization of various organic compounds which are unstable in storage, transportation; during'tre'atment and/ or in use with the resultant forma tion of undesirable gum, discoloration, rancidity and/or other deleterious reaction products. Specific illiis'trations of organic compounds which maybe treated in accordance with the present invention include motor fuel,

particularly un-saturated gasoline, jet fuel, dieselffue1,

' mineral -oil, lubricating oil, fuel oil, drying oil, 'gre ases, waxes, plastics, resins,rubber, edible fats and oils, forage crops, monomers including styrenef-butadienc; isoprene, acetylenes, etc, unsaturated acids, ketones, 'ald'ehydes, alcohols, etc. a

stabilization of hydrocarbons, including motor fuel and' still ,moreparticularly unsaturated gasoline ,as, EfOI'.}-6X- ample, cracked gasoline, coker distillate, polymer gaso- The invention also is applicable to the treatstgaightrunrgasclines, etc. I

findpartic ular use in the stabilization of-fatty materials,

includingrbothsolid and liquid; It;- is especially applicableto thestabilization of;.edib1e fats and oils, which-may bctof; animal, vegetable orv mineral origin'and which-tend.

to be me ranc'id especially during-long periods of :stora or to: use. Iypical representatives of edible. fats an OllS include linseed oil, -menhaden :oil, cod liver oil,

c roiLLolive oil, .rapeseedpil, coconut coil, gpalm oil,

c551 oil, sesame oil, peanuttoil babassu .oil, ;butter,- .f -at;;

lard, beef tallow, etc. It is understood that other oils and fats may be treated \vittfimthe scope of .the present invention,;i ncluding oils and fats which previously v have beens'ubjectedio various treatments, such as'lblowing with,airfheatreatnient,hydrogenation,Iletc; Q nlanb'th ju bodimenttheilpresent invention-may be a' 'lied' to 'th treatment of cropsfby I dusting Tor spraying in orderto' preserve food accessory factors such as :carotene,-;\titamins, various gfattyaacids; alcohols,-.etc. f

gil -he partieular antioxidant composition of the :present invention -.otfers @numerous ad-vantages iover the :use of;

either go)? the components .alone; =.In the rfirstnplace, one

of,. theant ifoxidants is tconsiderably more expensive than I the other antioxidant, and it hasriheenfoundr that our-1..

Un ed S airs P ten 0 1 2 ,843,495 Patented July fl5,

fllhe present-invention isparticularly-applicable to the l I may be effected by employing a'niixture of the fantioXidantsas compared 'to the stabilization obtained when employing the more expensive tantioxidant alone. It readily can be seen that this ofiers a 'very important ad vantage from a commercialviewpoint because it may per-, mit the commercializationof such a mixture, whereas the use of a larger concentration of the more expensive additive may be economically funfeasible. Another important advantage to' the" use of the mixturefis thatit has alower meltingipoint and, therefore, may be utilizetl x as a liquid mixture whichofiers some advantages in 'incorporatingthe antioxidant in the organic compositionito be stabilized. Furthermore,"the mixture is of increased solubility'in most -substrates;and, therefore,frnay"be' utilized more readily for the purpose. 'Still"furtl1er, '-the1 V 7 use of the improved mixture of the present'invention has greater applicability because, as happens with many. antioxidants, one is more effective in one substrate whilcthe other'may be more 'elfective in another substrate and thus I over-all improved stability is 'obtaincd'in a greater variety of-substrates than would be obtained with only-oneof" the components. a V I 9 In one embodiment, the present invention relatesjto a method of s'tab'iliz'ing an organic-compound against deterioration which comprises incorporating therein astabilizing amount of botha' 2,4;6-trialkylphen0l and a' 5 hydroxycoumara'n." v y v f In a ispecific embodiment the present invention relates to a method off stabilizingcracked gasoline which comprises incorporating therein from about""0.Q00-1% to about 1% :by weight of 'an antioxidant composifioncom' prising'from i'about20 to"about=30% by weight of 2,6-ditert butyll methylphenol and the *remainder -2,2-dimethyl-6-tert butyl-5ahydroxycoumarani 1 l :In -another specific' embodiment, the present invention relates :to ;a method of s'tahilizing fatty material against rancidity which comprises incorporating therein from about 0.0001% to about 1% by weight ofyan'antioxidant composition comprising from about 20 to about 80% by weight of 2,6-di-tert-butyl 4-methylphenol and the =r e- 'mainder 2,2 dimethyl-6-tert-butyl-5 hydroxycournaran.

-In' still another embodiment the present invention re- 1811653110 an organic :substanc'e "subject to oxidativedeterio ration containing ajstabiliiin-g zamountixof iheiantioxidant compositonhereinsetforth. i

In still another embodiment the present invention re! lates to an, antioxidant composition icomprisinga 2;436- trialkylphenol and a- 5.hydroxyco.umaran. v f

As hereinbefore set:forth,the novel :antioxidant :com'

positioncomprises both a 2,4;6-tr'ia'lkylpht'enol :arid e25 hydroxycoumaran. A preferred 2,4,6-trialkylphenol'ifor V and :similar compounds inwhichvthe methyl zgroup is irez tert-butyl group is replaced by. isopropyl, tert-amyl, terthexyl, tert-heptyl, tert-octyl, tert-nonyl, tert-decyl, terttributylplienol,"

: 3 phenol, 2,4,6-trioctylphenol, etc. It is understood that a mixture of trialkylphenol compounds may be used in the antioxidant composition.

.Apreferred S-hydroxycoumaran comprises 2,2-dimethyl-6-tert-butyl 5 hydroxycoumaran. Other 5 hydroxycoumarans include 2 methyl-6 tert-butyl-5-hydroxycour'naran, 2-methyl-6-sec-butyl-5-hydroxycoumaran, 2,2-dimethyl-6-sec-butyl-S-hydroxycouniaran, 2 -methyl 6 isopropyl-S-hydroxycoumarrn, 2,2-dimethyl-6 isopropyl- 5 hydroxycoumaran, Z-methyl-6-tert-amyl-5-hydroxycoumaran, 2,2-dimethyl-6-tert-amyl-5-hydroxycoumaran, etc., 2- methyl-S-hydroxycoumaran, 2,2-dimethyl-5 hydroxycoumaran, 2-methyl-6-cyclohexyl-5-hydroxycoumaran, 2,2-dimethyl-6-cyclohexyl-5-hydroxycoumaran, 2-methyl-6-benzyl-S-hydroxycoumaran, 2,2-dimethyl-6-benzyl-S-hydroxycoumaran, etc. Other inhibitors include those in which the alkyl-substituted in the 6-positioncomprises alradical' selected from n-propyl, n-butyl, n-amyl, etc. It is understood th at a mixture of S-hydroxycoumarans may be employed.

It is apparent that numerous compounds may be utilized in accordance with the present invention. However, all of these mixtures will not necessarily be equivalent in the same or different substrates. Furthermore, it is understoodthat the antioxidant composition may contain additional components, which usually will depend upon the particular substrate being treated. For example, when utilized in gasoline, various dyes, metal deactivator, antiknock agent such as tetraethyllead, iron carbonyl, etc., rust inhibitor, etc., may be employed. When used in edible fats and oils, certain acids such as citric acid, phosphoric acid, ascorbic acid, etc., may be employed. In some cases, it may be desirable to include one or more additional antioxidants in the composition.

The antioxidant composition may be utilized as such or, when desired, may be dissolved in a suitable solvent, including alcohols, aldehydes, ketones, glycols, etc. When used in food products, the solvent preferably comprises propylene glycol, glycerine, etc. When used with other additives all may be included in the antioxidant composition 'and the composition marketed as a mixture of manifold purposes.

The antioxidant composition will be utilized in a stabilizing amount. In general, this amount will range from about 0.0001% to about 1% by weight of the substrate. However, for certain uses the antioxidant composition may be employed in larger concentrations, which generally will not exceed about 8-10% of the substrate. For example, comparatively large concentrations of additives are used in rubber, etc.

The proportions of 2,4,6-trialkylphenol and S-hydroxycoumaran may vary considerably depending upon the'particular substrate to be treated. In general, the antioxidant composition will contain from about 20% to about 80% by weight of each of these components. These percents are based upon the 2,4,6-trialkylphenol and S-hydroxycoumaran only and are exclusive of solvents and other components in the composition. When employed, the solvent may comprise from about 10% to about 90% of the total antioxidant composition and usually will be within the range of from about 25% to about 75% of the total antioxidant composition.

It generally is preferred to form a mixture of the 2,4,6- trialkylphenol and S-hydroxycoumaran and to incorporate the mixture into the substrate. However, when desired, one component may be added first and the other component subsequently added to the substrate.

The following examples are introduced to illustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.

EXAMPLE 1 ablank or. uninbibited inductionperiod of 6O minutes.--

butyl-4-me'thylphenol.

The 2,4,6-trialkylphenol of this example is 2,6-di-tert- The S-hydroxycoumaran is 2,2- dimethyl-6-tert-butyl-S-hydroxycoumaran. The results of utilizing each of the components separately in a concentration of 50 parts per million in the gasoline and of using a 50-50 weight percent mixture of these components in a total concentration of 50 parts per million are shown in the following table:

Table I Antioxidant: Induction period, minutes None 60 2,6-di-tert-butyl-4-methylpheno1 250 2,Z-dimethyI-G-tert-butyl-S-hydroxycoumaran 405 5050 mixture of above 395 EXAMPLE n The results of using each of the components in a concentration of parts per million and a 50-50 mixture thereofi in a total concentration of 100 parts per million in-other samples of the same gasoline as described in Example I are shown in Table II. Table II Antioxidant: 7 Induction period, minutes None 60 2,6-di-tert-butyl-4 methylphenol 365 2,2-dimethyl-6-tert-butyl-S-hydroxycoumaran 545 50-50 mixture of above 520 Here again it will be noted that the expected induction period when using the 5050 mixture would be 445 minutes. On the other hand, the actual induction period obtained through the use of the mixture is 520 minutes.

EXAMPLE III This'exarnple illustrates the results of using the additives in lard having a normal stability of 2 hours as determined by the Swift Test. This test is described in detail in the article by A. E. King, H. L. Roschen'and W. H. Irwin, which appeared in Oil and Soap, vol. X, No. 6, pages 106-109 (1933), and modified as described in the article by R. W. Reimenschneider, I. Turer and R. M. Spec, which appeared in Oil and Soap, pages 169-171, September 1943. In general, this test comprises bubbling" air through a sample of the lard and determining rancidity organoleptically and by peroxide values.

The results when using 0.01% by weight of 2,6-ditert-butyl-4-methylphenol, 0.01% by weight of 2,2-dimethyl-6-tert-butyl S-hydroxycoumaran and of using a total of 0.01% of a mixture comprising 25% by weight of 2,6-di-tert-butyl-4-methylphenol and 75% by weight of 2,Z-dimethyl-6-tert-buty1-S-hydroxy coumaran are showniin the following table:

Table III Antioxidant: Stability, hours None 2. 2,6-di-tert-butyL4-methylphenol 19. .2,2dimethyl-6-tert-butyl-5-hydroxycoumaran 25.0 25-75' weight percent mixture of above---" 29.0 It will be noted that in this case the mixture actually producedbetter results than were obtained through the use of either additive alone in the same concentration. Normally one would expect a stability of about 23 hours from the mixture, whereas actually of 29 hours was obtained.

Surprisingly it has been,

a stability period 5, EXAMPLE IV EXAMPLE V Paraflin wax may be stabilized against oxidatiye deterioration by incorporating therein 0.005% by weight of an antioxidant composition comprising 75% by weight of 2,6-di-tert-amyl-4-methy1phenol and 25% by I Weight of 6-tert-octyl-5-hydroxy-coumaran.

I claim as my invention: 7 V 1. A method of stabilizing an organic compound selected from the group consisting of gasoline and lard against deterioration in storage which comprises incorporating therein a stabilizing amount of both' a 2,4,6- trialkylphenol and a S-hydroxycoumaran, at least one of the alkyl groups in the 2- and 6-positions of said trialkyl phenol being of' branched chain configuration.

2. An organic compound selected from the group consisting of gasoline and lard subject to deterioration in storage containing a stabilizing amount of both a 2,4,6-

trialkylphenol and a 5-hydroxycoumaran, at least one 6 of the alkyl groups in the 2- and 6-positions of said trialkyl phenol being of branched chain configuration.

3. Gasoline stabilized against oxidative deterioration containing a stabilizing amount of an antioxidant composition comprising a 2,4,6-trialkylphenol and a 5-hydroxycoumaran, at least one of the alkyl groups in the 2- and 6-positions of said trialkyl phenol being of branched chain configuration.

4. Cracked gasoline containing from about 0.0001%.

to about 1% by weight of an antioxidant composition comprising 2,4-dimethyl-6-tert-butylphenol and 2,2-dimethyl-6-tert-buty1-S-hydroxycoumaran. V

5. Cracked'gasoline containing fromabout 0.001% to about 1% by weight of an antioxidant composition comprising 2,6-di-tert-butyl-4-methylphenol and methyl-6-tert-buty1-5-hydroxycoumaran. I

6. Lard subject to rancidity containing from about 0.0001% to about 1% by weight of an antioxidant composition comprising 2,6-di-tert-butyl-4-methylphenol and 2,2-dimethyl-6-tert-butyl-S-hydroxycoumaran.

7. Lard subject to rancidity containing'from about' 0.0001%- to about 1% by Weight of an antioxidant composition comprising 2,6rdi-tert-butyl-4-methylphenol and 2-methyl-6-tert-butyl-5-hydroxycoumaran.

References Cited in the file of this patent UNITED STATES PATENTS 1,945,521 Downing .Feb. 6, 1934 2,599,810 Chenicek et al Iune.10, 1952 2,721,804

Rosenwald Oct. 25, 195.5 

1. A METHOD OF STABILIZING AN ORGANIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF GASOLINE AND LARD AGAINST DETERIORATION IN STORAGE WHICH COMPRISES INCORPORATING THEREIN A STABILIZING AMOUNT OF BOTH A 2,4,6TRIALKYLPHENOL AND A 5-HYDROXYCOUMARAN, AT LEAST ONE OF THE ALKYL GROUPS IN THE 2- AND 6-POSITIONS OF SAID TRIALKYL PHENOL BEING OF BRANCHED CHAIN CONFIGURATION. 